The present invention relates to a disc type optical information recording and reproducing apparatus. More particularly it relates to a movable mirror device for use in the apparatus of the type for reflecting a light such as a laser beam in a desired optical axis direction.
The conventional movable mirror device utilizes a movable permanent magnet disposed in a magnetic field produced by a stationary coil portion and a mirror bonded onto a surface of the permanent magnet. In the movable mirror device of this type, however, an important disadvantage is inherent in that an external magnetic field may be produced by a driving device for an objective lens for focussing the laser beam on a disc surface. This is apt to affect the movable mirror device.